Epoxy resins have been precatalyzed with phosphonium and other compounds to provide latent compositions which form advanced, higher molecular weight epoxy resins when admixed with an aromatic hydroxyl-containing compound as disclosed by Perry in U.S. Pat. No. 3,948,855 and Can. 893,191; by Dante et al. in U.S. Pat. No. 3,477,990; by Mueller et al. in U.S. Pat. No. 3,547,881; by Tyler, Jr. et al. in U.S. Pat. No. 4,366,295; and by Cragar in Can. 858,648.
While compositions containing these catalysts and an epoxy resin are somewhat stable, such compositions which also contain an aromatic hydroxyl-containing compound are lacking in stability.